// Copyright 2024, Pulumi Corporation.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package fsutil

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
)

var ErrNotFound = errors.New("not found")

// Searchup searches for a file in the current directory and then walks up the directory tree until it finds the file,
// returning the path to the file. If the file is not found, it returns ErrNotFound.
func Searchup(currentDir, fileToFind string) (string, error) {
	p, err := filepath.Abs(filepath.Join(currentDir, fileToFind))
	if err != nil {
		return "", fmt.Errorf("abs: %w", err)
	}
	if _, err := os.Stat(p); err == nil {
		return p, nil
	}
	parentDir := filepath.Dir(currentDir)
	if currentDir == parentDir {
		return "", ErrNotFound
	}
	return Searchup(parentDir, fileToFind)
}
